Sheet handling mechanism



Sept. 1, 1942. s. A. HUFFMAN SHEET HANDLING MECHANISM Filed Oct. 13, 1939 3 Sheets-Sheet 2 INVENTOR Sama/e/. Huffman Sept. 1, 1942. s. A. HUFFMAN SHEET HANDLING MECHANISM Filed Oct. 13, 1959 5 SheeS--SheefI 3 Samue72 fman @al aw JA -Patented Sept. 1, 1942 SHEET HANDLING MECHANISM Samuel A. Huffman, Avalon, Pa., assignor to Miller Printing Machinery Co., Pittsburgh, Pa., a corporation of Pennsylvania Application October 13, 1939, Serial No. 299,309

4 Claims.

This invention relates to the art of handling sheets, for example the handling of sheets singly from a processing machine (such as a printing press or the like) and disposing of them in suitable condition for further handling. This application is in part a continuation of my copending application Serial No. 199,167.

The problem of handling sheets is encountered in various industrial operations. The best known of such applications is the feeding of sheets to a printing press and the delivery of sheets therefrom. This invention is particul`arly adapted to such application and will be described with special reference to the delivery of sheets from a printing press, although the invention is not limited to this application but has other uses as well.

Sheet handling mechanisms for printing presses have heretofore included reciprocating members of considerable mass. Any attempt to operate such equipment at high speed introduces objectionable stress, shock and vibration. It is an object of the invention, therefore, to improve generally` on sheet handling mechanisms as known heretofore, anad particularly to avoid reciprocating parts to a large degree, thus permitting high speed operation without the aforementicned, objectionable stress, shock and vibration.

In accordance with the invention I employ endless belts for advancing sheets successively. The belts travel over a suitably formed table or other support and I provide vacuum means for progressively holding a sheet in contact with the travelling belts.. The application of vacuum to the sheet at each point Ain its path of travel is controlled automatically to insure the desired moyement without crumbling or other injury to the sheet.

The invention may take numerous different forms, and the following, detailed description will cover only one of the numerous possibilities.. The form of the invention to be describedherein with reference to the accompanying drawings is a conveyor adapted to receive sheets successively from a printing press and deliver them to a suitable pile support.

In the drawings:

Figure 1 is a plan view of a conveyor mechanism adapted to receive sheets after passing through a press and deliver them to a suitable pile support;

Figure 2 is a side elevation thereof; n

Figure 3 is a fragmentary elevational view showing the driving means for the perforated belt and for the vacuum controlv valve;

Figure 4 is an elevation of the stator of a rotary valve employed to controlv the vacuum applied progressively to the sheets for holding them in contact with the conveyor belt;

Figure 5 is a sectional view through the stator and rotor of the valve taken along the line V-V of Fig. 4; and

Figure 6y is an 'elevation of the rotor of the valve. A

The principle of the invention is applicable to the delivery of sheets singly after processing in any sort of machine such as a printing press, and piling them vaccurately on a suitable support. Such a structure is shown in the drawings. As there shown, a delivery board 300 has vacuum ports spaced therealong adapted to cooperate with a perforated belt 302. The belt 302 is trained about guide sheaves 303, a driving sheave 304 and a tightener sheave 305. lThe driving sheave 304 is mounted on a shaft 3||4a so as to rotate therewith. 'I'he shaft 304er is journalled in side arms 304i) and 304c to ,which the delivery board 300 is secured. The tightener sheave 305 is mounted on links 305e pivoted to the side arms 304D and 303e. Keyedto the shaft 304a is a sprocket 303 through which the shaft is driven at variable speed by a sprocket chain 308a which in turn is operated by mechanism now to be described.

A sprocket |93 -is journaled on a bearing bracket |94 dependent from a portion |50 of the side frame. The sprocket chain 308a Ameshes with the sprocket |93. A crank |95 is journaled on a shaft |96 extending laterally from the side Aframe portion |56 and has a slide |91 thereon and which reciprocates a block |98. A crank |99 carried by the sprocket |93 has a pivotal connection with the block |98. The crank is driven from a constant speed drive shaft by a chain and sprocket drive 200.

It will be apparent that the elements just described cause the sprocket |93 to move at maximum angular velocity when the throw of the crank |95 is a maximum, i. e., when the crank and the parts of the drive mechanism are so dimensioned and arranged that the belt 302 travels at its minimum speed when vacuum is applied to the port 30| nearest the right hand end of the delivery board 300 in a manner presently to be described. By this means a sheet advanced by the belt 302 is decelerated almost to a standstill on approaching the right hand end of the delivery board.

In order to cause the belt 302 to advance a sheet delivered thereto over the delivery board 300 to a pile indicated at 250 from the cylinder of a press or other mechanism (not shown) disposed at the left of the delivery mechanism, I provide means for applying vacuum progressively to the ports 30|. The belt 302' has a series of longitudinally spaced perforations 302a. through which vacuum applied to the ports 30| causes a sheet delivered to the board 300 to be held against the belt 302 by atmospheric pressure. I provide a rotary valve for controlling the application of vacuum to the ports 30| in a manner such that the point at which vacuum is applied at any instant will coincide substantially with the position of the leading edge of a sheet moving along the board at that instant. The valve is shown in Figs. 4 through 6 and is indicated generally in Figs. 1 through 3 by the numeral 306. The valve comprises a stator 14 and a rotor 15. The stator has feet 16 whereby it is secured to pads formed on the side of the board 300. The stator has a tapered bore and the rotor is correspondingly shaped for cooperation therewith. Ports 11 are spaced circumferentially of the bore through the stator. Hose connections (not shown) extend between fittings screwed into tapered holes in the stator 14 and the board 300. communicating respectively with the ports 11 and the ports 30|. A main vacuum port 13 formed in the stator 14 is similarly connected to a vacuum pump (not shown).

An annular groove 80 is formed in the rotor 15 and is so positioned axially thereof as to overlie the port 18. A recess 8| formed in the rotor communicates with the groove 80 and is adapted successively to overlie the ports 11 on rotation of the rotor. By this means the ports 30| are successively connected to the vacuum pump as the recess 8| passes over the ports 11 to which the ports 30| are connected. As shown in Fig. 6, the recess 8| is wide enough to overlie two adjacent ports 11 simultaneously. 'I'his insures that at least one of the ports 30| will have vacuum applied thereto at all times, or, in other words, that before vacuum is cut off from one port it will be applied to the next succeeding port. Continuous traction of the belt 302 on the advancing sheet is thus assured.

'I'he rotor 15 is keyed to a shaft 82 having a. flange 83 engaging a bearing surface 84 on the stator 14. The shaft 82 carries a gear 86 meshing with a pinion 81 keyed to a stub shaft 88. The pinion 01 meshes with a pinion 89 keyed to a stub shaft 80. Also keyed to the stub shaft 80 is a pinion 8| which meshes with a pinion $2 keyed to the shaft 304a. Thus the rotor 15 of the valve 300 is driven from the shaft 304a in timed relation with the delivery of sheets to the left hand end of the board 300. Hold-down tapes 308 may be driven at the same speed as the belt 302 by a drive (not shown) deriving its power from the shaft 304e.

Pile supporting frame members 3|0 are carried on a base 3|| which may be the side frames of a printing press if the delivery is installed in connection with this particular type of sheet processing machine. A pile support 3I2 is suspended from the members 3|0 by cables and pulleys. Automatic lowering means for the' support 3|2 include a ratchet wheel 3|3 adapted to be advanced periodically by pawl 3|4 on an oscillating crank 3|5. The ratchet wheel is geared to a shaft 3|6 through suitable reduction gearing (not shown) and the cables suspending the support 3I2 are wound on drums 3|1 on the shaft. The crank 3|5 is oscillated by a link 3|8, a bell crank 3|8 and a push rod 320. The latter is reciprocated by any suitable means in timed relation with the delivery of sheets.

Sheets delivered to the board 300 are moved therealong by the belt 302 because of the application of vacuum successively to the ports 30|, thus serving to hold the learing edge of each sheet tightly against the traction belt. When the leading edge of the sheet reaches the end of the board 300, it is beyond the zone of the last vacuum port 30| and is thus free to move away from the belt. Deflector members 32| guide the sheets downwardlyv onto the pile as they are discharged from the end of the delivery board. 'I'he frame members 3| 0 are provided with the usual Jogger box 322 and operating mechanism therefor whereby the sheets are piled accurately and squarely.

It will be seen from the above description that the travelling vacuum belt provides a very effective means for delivering sheets successively after processing to a pile support for stacking. I find it particularly advantageous to operate the belt at variable speed and so timed relatively to the movement of the articles being delivered thereto as to receive such articles while the belt is moving at approximately the same speed as that at which the articles are themselves moving when delivered to the belt. This is preferably approximately the maximum speed of movement of the belt during its variable speed movement and preferably the articles are carried by the belt and their speed is 'reduced while they are being so carried and they are discharged or delivered from the belt at the delivery end thereof when the belt is moving relatively slowly and preferably when its speed is approximately the minimum. 'I'his is of particular advantage in the delivery of sheets from a printing press or similar mechanism to a pile as the sheets are moving at fairly high speed when delivered from the press and must be brought to a stop when delivered to the pile. Preferably the maximum speed of the belt is approximately equal to the speed of delivery of the sheets from the press and the minimum speed of the belt is reached during each cycle at approximately the time when a sheet is delivered from the delivery end of the delivery mechanism.

Although I have illustrated and described herein but a preferred form of the invention, it will be understood that changes in the construction and operation disclosed may be made Without departing from the spirit of the invention or the scope of the appended claims.

I claim:

l. A sheet delivery for a printing press comprising a continuously driven belt conveyer upon which the sheets are adapted to be discharged at relatively high speed from the printing press, means for driving the conveyer at relatively high speed when a printed sheet is delivered to it and for thereafter rapidly decelerating the movement of the conveyer for delivering the printed sheet therefrom at a relatively low speed, and means for applying suction progressively effective in timed relation to the movement of the conveyer for holding down the printed sheet against the conveyer so as to prevent curling and skiddng of the printed sheet on the conveyer as the movement of the conveyer is decelerated.

2. Sheet conveying apparatus comprising a continuously driven belt conveyer upon which sheets are delivered at a relatively high speed, means for driving the conveyer at approximately the speed of a sheet as delivered to it and then rapidly decelerating the movement of the conveyer so as to deliver the sheet therefrom at a relatively low speed, and means for applying to the sheet a suction progressively effective in timed relation to the movement of the conveyer4 sheets are delivered at one speed, means for driving the conveyer at a speed approximating that of a sheet as it is delivered to the conveyer and for thereafter rapidly changing the speed of the conveyer to deliver the sheet therefrom at a different speed. and means for applying to the sheet a suction progressively effective in timed relation to the movement of the conveyer for holding down the sheet against the conveyer so as to prevent curling and skldding of the sheet on the conveyer as the speed of the conveyer is changed.

4. Sheet handling mechanism for handling sheets in connection with a printing press or the like comprising a variable speed belt conveyer upon which sheets are adapted to be moved and means for applying suction progressively effective in timed relation to the movement of the conveyer for holding down the sheets against the conevyer so as to prevent curling and skidding of the sheets on the conveyer as the speed of movement of the conveyer changes.

SAMUEL A. HUFFMAN.

CERTIFICATE oF cRREcTIoN.

Patent No. 2,291hho7. september 1, 19142.A

SAMUEL A. HUFFMAN.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring co rrectionas follows: Page 2, first column, line 57, for tapered read tapped-g and that the said Letters -Patent should be read with this correction therein that the same may confonn m the record o'f me case in the Patent office.

Signed and sealed this 6th day of October, A. D. 194.2.

Henry Ven Arsdale,

(Seal) Acting Commissioner of Patents. 

